Police were called to the scene at about 13:40 BST after the suspect had been detained by members of Shomrim, a Jewish neighbourhood watch group. The women are believed to have suffered minor injuries.
Chief Inspector Erica Crawshaw described the incident as "an alarming and distressing incident" and thanked Shomrim volunteers for detaining a suspect before officers arrived. "We recognise the concern that this incident will have caused the Jewish community here in Hackney," she said. "We have increased patrols in the area and we are speaking to community leaders to provide further reassurance."
The man was initially arrested on suspicion of racially aggravated common assault. He has since been further arrested on suspicion of grievous bodily harm in connection with a separate incident in Islington on Friday, the force said. He remains in custody.
The Met has appealed for anyone with information, or anyone else who believes they may have been assaulted, to come forward.